[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Environmental pathology](https://durgical.com/en/general-pathology/#a-environment) › Air pollution and occupational exposures

[General pathology](https://durgical.com/en/general-pathology/) · [Environmental pathology](https://durgical.com/en/general-pathology/#a-environment)

# Air pollution and occupational exposures

- Topic

Polluted air outdoors, smoke from cooking fires indoors and dusts at work damage the lungs and the heart, and some cause cancer.

Updated 2026-11-01

## Key points

- Silicosis: upper lobes, eggshell calcification, increased tuberculosis.
- Asbestos: lower lobes, pleural plaques, ferruginous bodies, mesothelioma; lung carcinoma is still the most common asbestos cancer.
- Berylliosis resembles sarcoidosis: non-caseating granulomas.
- Carbon monoxide: high affinity for haemoglobin, left shift, normal pulse oximetry, cherry-red colour after death.
- Biomass smoke from indoor cooking causes COPD in non-smoking women.

## What it is

The lung filters a huge volume of air every day. Fine particles, ozone and gases inflame the airways and reach the blood; mineral dusts are engulfed by macrophages that then drive fibrosis. Household smoke from wood or coal used for cooking is a major cause of disease in rural Latin America, and many workplace exposures cause specific diseases and cancers.

## Key facts

- Carbon monoxide binds haemoglobin far more tightly than oxygen and shifts the curve to the left; pulse oximetry looks normal.
- Severe carbon monoxide poisoning can cause necrosis of the globus pallidus.
- Radon in homes and mines is the second cause of lung cancer after tobacco.
- Occupational cancers: benzene → leukaemia; vinyl chloride → liver angiosarcoma; aromatic amines in dyes → bladder cancer.

## Step by step

- Large particles stay in the nose and bronchi; the finest reach the alveoli.
- Alveolar macrophages engulf the particles and release cytokines, free radicals and growth factors.
- Toxic dusts such as silica kill the macrophages, which release them again and keep the cycle going.
- Fibroblasts lay down collagen: nodular or diffuse fibrosis of the lung (pneumoconiosis).
- Fine particles and ozone also act on the blood and vessels: endothelial inflammation, thrombosis and arrhythmia.

## Dusts and the lung disease they cause

| Exposure | Lesion | Distinctive feature |
| --- | --- | --- |
| [Coal dust](https://durgical.com/en/conditions/pneumoconioses/) | Anthracosis, coal workers' pneumoconiosis, massive fibrosis | Upper lobes; Caplan syndrome with rheumatoid arthritis |
| [Silica (quarries, sandblasting, mining)](https://durgical.com/en/conditions/pneumoconioses/) | Silicosis with fibrotic nodules | Upper lobes, eggshell calcification of hilar nodes, higher risk of tuberculosis |
| [Asbestos (insulation, shipyards, brakes)](https://durgical.com/en/conditions/pneumoconioses/) | Asbestosis, pleural plaques, mesothelioma, lung cancer | Lower lobes; ferruginous bodies; strong synergy with smoking |
| Beryllium (aerospace, electronics) | Chronic berylliosis | Non-caseating granulomas, like sarcoidosis |
| [Organic dusts (mouldy hay, birds)](https://durgical.com/en/conditions/hypersensitivity-pneumonitis/) | Hypersensitivity pneumonitis | Immune reaction with poorly formed granulomas |

## Memory aid

Coal and silica climb to the top of the lung; asbestos sinks to the base and lines the pleura.

## Test yourself

Think of the answer, then tap the question to see it.

## Why does silicosis raise the risk of tuberculosis?

Silica damages alveolar macrophages and their ability to kill mycobacteria.

## What is a ferruginous body?

An asbestos fibre coated with iron-protein material, golden-brown and beaded, seen in lungs exposed to asbestos.

## Why is pulse oximetry misleading in carbon monoxide poisoning?

The oximeter reads carboxyhaemoglobin almost like oxyhaemoglobin, so saturation looks normal while oxygen delivery is low.

## Which occupational dust disease looks like sarcoidosis under the microscope?

Chronic berylliosis, with non-caseating granulomas.

[Add to my cards (4)](https://durgical.app/estudiar/?add=/en/general-pathology/air-pollution-and-occupational-exposures/)

## Related

- [Tobacco: how smoking injures tissue](https://durgical.com/en/general-pathology/tobacco-how-smoking-injures-tissue/)
- [Chemical carcinogens: initiation, promotion and the table to know](https://durgical.com/en/general-pathology/chemical-carcinogens-initiation-promotion-and-the-table-to-know/)
- [Fibrosis in organs: TGF-β and the myofibroblast](https://durgical.com/en/general-pathology/fibrosis-in-organs-tgf-and-the-myofibroblast/)
- [Granulomatous inflammation: caseating vs non-caseating, the causes to know](https://durgical.com/en/general-pathology/granulomatous-inflammation-caseating-vs-non-caseating-the-causes-to-know/)
- [Pigments in tissue: lipofuscin, hemosiderin, melanin, bilirubin, carbon](https://durgical.com/en/general-pathology/pigments-in-tissue-lipofuscin-hemosiderin-melanin-bilirubin-carbon/)
- [Heavy metals: lead, mercury, arsenic and cadmium](https://durgical.com/en/general-pathology/heavy-metals-lead-mercury-arsenic-and-cadmium/)

## Related conditions

- [Pneumoconioses (silicosis, asbestosis, coal workers' pneumoconiosis)](https://durgical.com/en/conditions/pneumoconioses/)
- [Chronic obstructive pulmonary disease (COPD)](https://durgical.com/en/conditions/chronic-obstructive-pulmonary-disease/)
- [Carbon monoxide poisoning](https://durgical.com/en/conditions/carbon-monoxide-poisoning/)
- [Malignant pleural mesothelioma](https://durgical.com/en/conditions/malignant-pleural-mesothelioma/)
- [Lung cancer](https://durgical.com/en/conditions/lung-cancer/)
- [Hypersensitivity pneumonitis](https://durgical.com/en/conditions/hypersensitivity-pneumonitis/)
- [Asthma](https://durgical.com/en/conditions/asthma/)
- [Interstitial lung disease](https://durgical.com/en/conditions/interstitial-lung-disease/)
- [Pulmonary tuberculosis](https://durgical.com/en/conditions/pulmonary-tuberculosis/)
- [Bladder cancer](https://durgical.com/en/conditions/bladder-cancer/)
- [Acute leukaemia (AML and ALL)](https://durgical.com/en/conditions/acute-leukaemia/)
- [Cyanide poisoning](https://durgical.com/en/conditions/cyanide-poisoning/)

## Elsewhere in DurgiPedia

- [Airway defenses, cough and mucociliary clearance](https://durgical.com/en/physiology/airway-defenses-cough-and-mucociliary-clearance/)
- [Carbon monoxide, methemoglobin and cyanide](https://durgical.com/en/physiology/carbon-monoxide-methemoglobin-and-cyanide/)
- [Oxygen transport and the dissociation curve](https://durgical.com/en/physiology/oxygen-transport-and-the-dissociation-curve/)
- [The alveolus: type I and II pneumocytes, surfactant, the blood–air barrier](https://durgical.com/en/histology/the-alveolus-type-i-and-ii-pneumocytes-surfactant-the-blood-air-barrier/)
- [The airway: from nose to bronchioles](https://durgical.com/en/histology/the-airway-from-nose-to-bronchioles/)
- [Monocyte and macrophage](https://durgical.com/en/immunology/monocyte-and-macrophage/)
- [Type III hypersensitivity (immune complexes)](https://durgical.com/en/immunology/type-iii-hypersensitivity/)

[← All of general pathology](https://durgical.com/en/general-pathology/)

Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [Ambient (outdoor) air pollution](https://www.who.int/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health) (World Health Organization, 2026); [Household air pollution](https://www.who.int/news-room/fact-sheets/detail/household-air-pollution-and-health) (World Health Organization, 2026); [Carbon monoxide poisoning: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/002804.htm) (MedlinePlus, US National Library of Medicine, 2026).

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Representative model, for educational purposes only.

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License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/air-pollution-and-occupational-exposures/